1. Field
The present embodiments relate to a heterocyclic compound and an organic electroluminescent device comprising the same, and more particularly, to a heterocyclic compound having a high electrical stability, a high charge transporting capability, a high glass transition temperature, and a crystallization preventing capability, and an organic electroluminescent device including an organic layer comprising the same.
2. Description of the Related Art
Electroluminescent devices are a self-emission type display device and have a wide viewing angle, a high contrast ratio, and a short response time. Due to such characteristics, electroluminescent devices are getting more attention. Electroluminescent devices are generally classified into inorganic electroluminescent devices including an emitting layer employing an inorganic compound and organic electroluminescent devices including an emitting layer employing an organic compound. Specifically, organic electroluminescent devices have higher luminescent characteristics, a lower driving voltage, and a shorter response speed than inorganic electroluminescent devices. In addition, organic electroluminescent devices produce various colors. Due to those characteristics, much research into organic electroluminescent devices is being performed. In general, an organic electroluminescent device has a stack structure of anode/organic emitting layer/cathode, or when a hole injection layer and/or a hole transport layer and/or an electron injection layer are further stacked between the anode and the emitting layer or between the emitting layer and the cathode, a stack structure of anode/hole transport layer/organic emitting layer/cathode or a stack structure of anode/hole transport layer/organic emitting layer/electron transport layer/cathode.
Meanwhile, a polyphenyl compound or anthracene derivatives are well known as a hole transport layer forming material (see U.S. Pat. No. 6,596,415 and U.S. Pat. No. 6,465,115). However, organic electroluminescent devices employing conventional hole injection layer and/or hole transport layer forming materials still needs to be improved in terms of lifetime, efficiency, and power consumption.